Radio selector drive



Nov. 6, 1934. FfSPANGLER RADI [O SELECTOR DRIVE Filed March 19, 1931 Hank Spa/flew Patented Nov. 6, 19 34 PATENT OFFICE RADIO, SELECTOR DRIVE Frank Spangler, Dayton, Ohio, assignor, by mesne assignments, to Radio Corporation of America, New York, N. Y., a corporation of Delaware Application March 19,

9 Claims.

mechanism that makes for-a slow motion, and

smooth drive, of .a tuning shaft or other movable member, by a control shaft.

It is one of the objects of the instant invention to provide ,a slow motion drive that is simple in construction, and that can be formed by high' speed production methods.

A further object of the invention is to provide a drive mechanism in which the driving connection is maintained in a condition of smoothness of operation.

A further object of the invention isto provide a selector drive mechanism, in which the control shaft can be maintained in correct position with respect to its enclosing panel.

A further object of the invention is to provide a friction drive connection between a pair of movable parts, and yet maintain at least one of the movable'parts strictly normal relative to its enclosing casing.

A still further object of the invention is to.

provide a driving connection between two rotatable shafts, one of which is movable laterally relative to the other, yet is maintained in its predetermined angular relation.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawing:

Fig. 1 is a. view partly in elevation and partly in section illustrating the instant invention as adapted to a tuning or movable element of a radio receiver, the view being taken substantially as indicated bythe line and arrows 1-1 of Fig.

Fig. 2- is an elevational view, with a portion in section, illustrating the invention substantially as seen along the line andin the direction of the 1931, Serial No. 523,763 1 (01. 74-40) carried by a part of the apparatus within, and the panel 21 is otherwise apertured as at 24 making for the passage of a control shaft. In apparatus of the class described there is provideda tuning element 30, (here illustrated as a condenser bank, though conceivably it may be any other form of tuning or movable element), having a shaft 31 and relativelyfixed bearings 32, and which carries at its end a driving disc or member 33, through the agency of a clamp collar 34 secured thereto by one or more set screws 35. Here let it be stated, that, though a disc 33 has been illustrated as a means of rotating the shaft 31, there is included within the perview of the instant invention the fact that the disc 33 may be a longitudinally movable plate or strip, with appropriate means for driving the movable element 31, but in all events it is proposed that the member 33 will carry a tuning or other scale member 36, that may be secured tothe member 33 in any preferred manner as by the rivets 37,. though the scale 36 may be of integral formation with the member 33. f

In all events it is proposed that the scale 36 should carry the graduating indicia 38, that durmg movement of the member '33 will pass by the aperture 23 through which the setting may be perceived. In the illustrated embodiment, the scale member 36 is preferred to be a translucent member that will allow a certain amount of .1

light from the illuminant 39 to pass therethrough, thus illuminating the graduations 38 as they pass by the inspection aperture 23. The illuminant or lamp 39 is appropriately supported by a bracket 40 fixed or otherwise secured to the shielding member or case 41, disposed about the tuning element 30, and the enclosure 41 is appropriately fixed or secured to a frame member 42 that in turn is or may be supported by the base 20. However, the illuminant 39 may be otherwise supported, even so as to shine directly upon the scale indicia 30, where a scale member 36 of opaque character is used.

Provision is made-for driving the member 33, whether it be a rotatable disc or an elongated plate, by frictionally coupling therewith a control shaft 45 journalled in a sleeve bearing 46 secured to a carriage 47 slidable upon or movable along a bracket member-48, that is 1 in turn secured to the frame 42 by screws such as 49. The shaft 45 after passing through the bearing 46 projects outwardly through the aperture 24 of the panel 21, where it. is provided with a control knob 50 by a set'screw 51 that may be threaded through a metallic insert 52 carried by the knob 50. The carriage 4'? is provided with oppositely extending ears 55 and 56, that are bent or folded over in substantial parallelism with the body of the carriage 47 so as to embrace or provide guideways allowing the carriage to slide along the bracket 48 substantially as indicated in Fig. 3, and the bracket 48 is provided with a large aperture 57 in the region of the bearing 46, that makes for clearance thereof so as to allow lateral movement of the shaft 45 with respect to the shaft 31, or to allow movement of the carriage 47 along the bracket 48, at least within certain limits.

This structure provides that the control shaft 45 will be in substantial alignmentwith the clearance aperture of the panel, and will also present the inner end 60 of the shaft in contiguous relation with the member 33, at which, provision is made for driving relation between the shaft 45 and the member 33 as will now be described. The member 33 is provided with a slot 61 that is substantially in alignment with the end of the shaft 60, the slot 61 being en larged at one end as at 62 permitting the endwise movement of the shaft 45 therethrough to a position substantially as indicated in Fig. 1. In the illustrated embodiment, where there is disclosed a driving disc 33 the slot 61 is of armate form and concentric with the shaft 31, the said slot being disposed near the outer periphery of the disc 33 so as to leave a driving rim 63, that presents an edge 64 that bounds the outer contour of the slot 61.

Where the member 33'conforms to a longitudinally movable plate the slot 61 would or might then be a straight one or otherwise appropriate therefor. To mate up with the provision of the slot 61, the inner end of the shaft 45 is formed with an undercut annular groove 65 or otherwiseformed so as to have an inclined or slanting wall 66, for engagement with the driving edge 64 of the plate when the parts are positioned as set out in Fig. 1 and the enlarged detail of Fig. 4.. This in effect provides a groove 65 that is narrower at the bottom than at the surface of the shaft, and of less magnitude than the gauge of the material from which the member 33 is formed. The extreme inner endof the shaft 45 is reduced to provide a spool like groove 67 within which is disposed a hooked end 68 of a spring 69 having its other end '70 anchored to a lug '71 that may be an upturned end of the bracket 48.

This structure makes provision for a smoothly operating frictional drive between a pair of movableparts throughout the entire range of movement, and without variation of frictional resistance, since the inclined surface 66 of the control shaft is maintained in engagement with the driving edge 64 through the substantial constant energy expended by the spring 69. The shaft 45 being journalled in its closely fitting sleeve bearing '46 is not subject to oscillation, and any lateral movement that may be urged by the spring 69 engaging the spooled end 6'7 may move the shaft and its bearing supported by the carriage 47, yet maintaining the said shaft 45 in its predetermined parallel relation with respect'to the shaft 31, and consequently maintaining the shaft 45. strictly perpendicular or normal to the surface of the panel 21 or within the predetermined angular relation in which it has been assembled.

As illustrated in the detail of Fig. 4, it will be seen that the inclined surface 66 of the shaft 45 is maintained by the spring 69, in contacting engagement with the driving edge 64 of the movable member 33, the inclined surface 66 being thus urged will crowd the driving rim 63 against the main stop of the shaft 45. These parts .being in substantial rolling engagement throughout any manipulation of the shaft 45, there will be little or no wear of the parts in engagement. Any wearing away of the parts that may thus obtain will be fully compensated by the possible lateral movement of the shaft 45 and its bearing 46, as provided by the slidable movement between the carriage 4'7 and the bracket 48.

Where it is so desired, the upper end of the bracket 48 may be apertured at in alignment with the shaft 31, so that the same may project therethrough and have a bearing in the said bracket, for which reason the upper end of the carriage 47 has been notched as at 81 to provide ample clearance to embrace the shaft, should it be desired to move the carriage upwardly so as to withdraw the control shaft 45. This proposed structure will tend to rigidify the bracket 48 supporting the control shaft 45, but it has been found to be perfectly satisfactory to allow the shaft 31 to fall short of the bracket 48 without having its end bearing in the bracket, since the sleeve bearing 46 supports the' shaft 45 without substantial oscillation, and which shaft also has its end engagement with the member 33 that is urged into such relation by the spring 69. Y

The control shaft 45 thereby is maintained in perpendicular relation with respect to the control panel, that makes for a better general appearance, and causes less trouble in assemblin of parts. Manipulation of the control knob 50 thereby drives the member 33 with smoothness and without variation in frictional resistance, causing the scale portion 36 to pass by the perceiving aperture 23 which of course marks the relative position of the part that is. being moved through the agency of the knob.

What is claimed is as follows:

1. A radio selector drive comprising in combination, a tuning shaft provided with a driven disc of thin material, a control shaft arranged parallel to said tuning shaft and having means frictionally engaging said disc, an elongated bearing sleeve for said control shaft having limited movement to and from said tuning shaft, and means engaging said control shaft for urging said frictional means into driving engagement with said disc.

2. A radio selector drive comprising in combination, a rotatable shaft carrying a driving disc, said disc having an arcuate slot substantially concentric with said shaft, a control shaft mounted for, lateral movement and arranged in substantial parallelism with said. tuning shaft, said control shaft having an undercut annular groove near one end thereof, said shaft projecting through the disc slot, and means urging the groove of said control shaft into receptive relation with said slot edge.

.3. A radio selector drive comprising in combination, a tuning element providing a rotatable shaft, a driving disc carried by said shaft and having an arcuate slotnear its -periphery concentric with said shaft, a control shaft, a bracket supporting the control shaft in substantial alignment with said slot, a carriage movable upon the bracket and providing a tubular bearing within which ,is journalled said con- .tained between said control shaft and said disc.

means engaging the bracketand the end of said shaft causing the shaft groove to seat upon the I outer edge of said disc slot, whereby driving engagement is maintained between the shaft and disc.

4. A radio selector drive comprising in combination, a movable element to be actuated by a control knob, with translating mechanism adapting the movement of the knob to actuation of the said element, said translating mechanism including a movable member operable to actuate said element and providing a slot having an enlargement, a. movable bearing, a control shaft journalled in 'the movable bearing substantially in alignment with said slot, said shaft being insertable through the enlargement of said slot and thence capable of movement therealong, and means urging the shaft into engagement with the movable member at one edge of said slot.

5. A radioselector drive comprising in combination, a rotatable shaft carrying a driving disc, said disc having an arcuate slot substan tially concentric with said shaft, a control shaft, a bracket secured in substantial parallelism with said driving disc, a tubular bearing slidably supported on said bracket, said control shaft having its journal in said bearing with its end projecting through said slot and a spring secured to the projecting end of the shaft for moving the shaft and bearing along the bracket and to maintain frictional driving engagement between the said shaft and driving disc.

6. A radio selector drive comprising in combination, a rotatable shaft carrying a driving disc, said disc having an arcuate slot substantially concentric with said shaft, 9. control shaft mounted for lateral movement and arranged in substantial parallelism with said tuning shaft, a tubular bearing forming. the sole support for said control shaft, a bracket and means slidably supporting the bearing upon said bracket, and

" means engaging the shaft so as to urge the bracket and its slidable support in a plane substantially parallel to 'that of the driving disc whereby frictional driving engagement is main- 7. A radio selector drive comprising in combination, a driving plate, a movable member to be driven by said plate, a control shaft substantially normal to said plate, .an elongated bearing sleeve journalling said shaft for rotation, means shif bly supporting said bearing and shaft, a bgacket rigidly supporting said means but pe tting lateral movement of said shaft and bearing to and. from the body portion of said plate, and means secured to said .shaft urging the same into engaging relation withthe body of said' plate, said shaft having an undercut groove for setting over the edge of said plate whereby the frictional engagement therebetween is increased.

, 8. In a device ofthe class described, the combination of a member to be adjusted, a thin disc secured to said member and provided near its periphery with an arcuate slot,.a shaft provided with an operating knob and mounting means for causing an end portion of said shaft to frictionally engage the edge portion of said "disc adjacent said slot, said mounting means comprising a sheet metal bracket extending parallel to the plane of said disc, a thin elongated metal plate having one surface engaging one surface of said bracket and provided at each end with a pair of bent over ears to engage the opposite surface of said bracket, and an elongated bearing sleeve secured to said plate and providing a journal bearing for said shaft.

9. A radio selector drive comprising in combination, a base plate, a device to be adjusted mounted on said base plate, a thin disc connected to said device and provided near its pe riphery with a curvededge portion, a bracket having an intermediate portion secured to said base plate and'two upstanding portions extending parallel to the plane of said disc, a carriage slidable along the first of said upstanding portions, a journal bearing secured to said carriage, an operating. shaft mounted in said journal bearing and provided with a reduced end portion, a coil spring having one end looped about said end portion and its opposite end secured to the secand of said upstanding bracket portions, said 

